Method of making cores for reinforced concrete or plaster floor construction.



C. F. HENNING. R REINFORCED CONCRETE 0R PLASTER FLOOR CONSTRUAPPLICATION FILED APR.9. 915.

CTION.

mnnoo OF MAKING cones F0 Patented May 30,1916.

UNITED STATES PATENT OFFICE.

CHARLES F. HENNING, OF CHICAGO, ILLINOIS, ASSIGNOB TO THE UNITED STATESGYPSUM COMPANY, OF CHICAGO, ILLINOIS, A CORPORATION OF NEW JERSEY.

METHOD OF MAKING- CORES FOR REINFORCED CONCRETE OR PLASTER FLOOR CON-STBUCTION.

Specification of Letters Patent.

Patented May 30, 1916.

Application filed April 9, 1915. Serial No. 20,162.

To all whom it may concern:

Be it known that I, CHARLES F. HENNING, a citizen of the United States,residing at Chicago, in the county of Cook and State of Illinois, havein ented certain new and useful Improvements in Methods of Making Coresfor Reinforced Concrete or Plaster Floor Construction, of which thefollowing is a specification.

My invention relates to a method of maleing a void-forming core adaptedto be utilized in concrete and laster floor construction to materiallydiminish the weight wlthout affecting the strength thereof.

In order to meet the requirements of a thoroughly satisfactory voidforming core for 1: :e in floor construction the core must be light inweight, strong and substantial, capable of being manufactured inrelatively large sizes, uniform in size and shape, capable of beingeasily fitted into position, fire and water proof and non-conductive ofsound.

It is an object of my invention to provide a simple and efiicient methodof manufacturing void-forming cores in which are combined the variousdesirable features above set forth.

Further objects and advantages of my invention will be apparent as it isbetter understood by reference to the following specification when readin connection wit the accompanying drawing in which- Figure 1 is aperspective view of a complete core ready to be placed in position; Fig.2 is a vertical section of a floor showing the cores disposed side byside and the manner of applying the ceiling plaster; Fig. 3 is avertical section through a sheet of plaster board of the type which Ipreferably employ in carrying out my invention.

Referring to the drawings, 1 indicates generally a core of plaster boardprovided with a top 2 and sides 3, having flanges 4 forming supportingfeet for the core and adapted to space the cores laterally when placedside by side as indicated in Fig. 2. The bottom 5, consisting of asingle sheet of plaster board is secured to the flanges 4 by means ofclipsfi of which any suitable number may be employed. The clips arepreferably of soft iron, easily bent in any desired direction and areprovided with upwardly extending tongues 7 adapted to be embedded in theconcrete as indicated in Fig. 2.

The method of making the cores is as follows: The plasterof-Paris, mixedwith water to the proper consistency and containing, if desired, acertain proportion of pulverized hardened plaster which acts as anaccelerator for the setting operation, is disosed between oppositesheets of a reinforcmg material, preferably a wool felt, and the mass issubjected to pressure whereby the plaster is forced into the intersticesof the felt and becomes incorporated therewith to form a strong bondbetween the felt and plaster. The result is a sheet of plaster boardwhich, while the plaster is still in a plastic condition, is molded inany suitable manner to the form indicated in Fig. 1. The plaster is thenallowed to set and the molded core is dried after which it is dipped inor otherwise coated with a suitable waterproofing material, such aspitch. The waterproofing material impregnates the surfaces of the moldedcore and not only waterproofs the structure but strengthens it to avconsiderable extent so that it is better able to withstand rough usagein shipment and the handling necessary during building operations. Themolded portion of the core is assembled with the bottom sheets 5 andsecured thereto by clips 6 at the job. The bottom sheets 5 may bewater-proofed if desired.

I have described my method in its simplest form and in connection with aplaster board consisting of a layer of plaster covered on either side bya sheet of reinforcing material. If desired the plaster board may bemade as in Fig. 4 and consisting of a plurality of layers of plaster 16and reinforcing material 17. The resulting plaster board is molded toform the cores exactly as in the preceding description.

Preferably the pressure to which the mass is subjected to force theplaster and reinforcing material together is exerted by suitable rollsso that the method may be continuous. In carrying out the method thecores may be molded in a continuous sheet of plaster oard and separatedafter the plaster is hardened or. if esired, the plaster board may becut into desired lengths while the plaster is still in the plasticcondition and subsequently' molded before the plaster hardens. It! stepw ll follo" the drying operation after which the cores, which are cut touniform and standard sizes, are ready for shipment.

In the use of my invention a suitable false-work is erected which needcomprise only beams spaced at intervals equal to the width of the coresand the cores with their bottoms secured in place by means of the clips6 are mounted in rows on the beams, end to end, and with the flanges 4of adjacent row engaging, as indicated in Fig. 2. Preferably theindividual cores of adjacent rows are disposed in staggered relation.lVhen all of the cores are in place the reinforcing members 8 are placedin position and the concrete 9 is poured and allowed to harden. Theconcrete enters the spaces between the adjacent rows of cores and formsbeam sections which, with the reinforcing members, support the load ofthe floor, The ceiling plaster 10 is applied directly to the bottomsheets 5 of the cores and owing to the nature of the reinforcingmaterial the ceiling plaster forms a strong bond with the sheets 5 whichwill hold the plaster in position indefinitely.

Plaster board is comparatively light in weight and a saving ofapproximately twenty-five pounds per square foot in the weigl'it of thecores alone is possible where plaster troa rd cores are substituted forthe clay tile of the prior art. A further saving is effected in theamount of concrete and steel necessary to sustain the dead-load of thefloor and both of these savings are transferred in turn to thesupporting colunms may be correspondingly lighter. Cores of plasterboard are also lighter than the cores of solid plaster, concrete orsheet metal of the prior art.

Cores of plaster board are strong and substantial, withstanding roughusage in shipment and setting, and are preferable to cla tile coreswhich are exceedingly brittle and sheet metal cores which are easilydented and deformed when repeatedly handled by careless workmen. Solidplaster cores are too fragile for commercial use and cement cores areobviously too heavy for economical shipment.

Plaster board cores may be made in relatively large sizes of uniformshape and size, whereas clay tile cores are limited in size owing todifliculty of firing. Clay tile cores are, even in the smaller sizes,always more or less warped and are, therefore, not uniform in shape.Sheet metal cores are so deformed by handling that they are rarely ofuniform shape when they reach the job. By the use of plaster board coreslonger spans are possible and a larger amount of space is therebypossible in a building of given size. The uniform shape of plaster boardcores allows r them to be more readily placed in position either casethe water-proofinglath but also to obtain a su face from the lower andinasmuch as the plaster board may be neatly cut and trimmed by means ofordinary carpenters tools a considerable saving in labor is effected bythe of these cores rather than those of the prior art which are cut withdifiiculty and are frequently spoiled during the cutting operation.

laster board is extremely resistant to fire and it will be readilyunderstood from the foregoing description and by reference to thedrawing, particularly Fig. 2, that by the use of my invention theunder-side of the concrete is protected from fire by two layers ofplaster board and in addition a large part of the undersurface isfurther protected by the dead air space within the cores. Furthermoreshould all or portions of the ceiling plaster be damaged, by fire forexample, and the bottom sheets 5 thereunder be injured, the ceiling maybe easily replaced or repaired by bending the clips and removing andreplacing the injured sheets with new sheets after which ceiling plastercan be applied to the new sheets as before. This can be done withoutinjury to the cores or floor structure and without necessitating thereplacement of any other parts than the bottom sheets, thereby greatlyreducing the cost of replacing or repairing the ceiling.

By the use of cores having plaster board bottoms to which the ceilingplaster may be directly applied a material saving in the cost ofplastering is effected. lVire lath has been universally used with metaldomes as a base to which the ceiling plaster is applied. This materialinvariably sags and a greater thickness of plaster grounds is requirednot only to securely bond the plaster to the wire flat ceiling, it beingob "ous that/the distance of the wire lath surface of the floorIsa-"greater at the center of the span than at i s ends owing to the sagof the wire lath. lVhen clay tile are used the ceiling surface is unevenand irregular and an excessive amount of plaster must be used to obtainuniform grounds. Plaster board not only bonds firmly with the withoutthe necessity of providing openings a flat surface. throughout the spanso that the thickness of the plaster grounds does not vary. The ceilingplaster is much more readily applied to plaster board than to wire lathsince the plastcr board presents a firm surface to the plasterer,whereas the wire lath moves up anv down at each application of theplasterer's tools.

The continuous ceiling the alternate light and dark lines caused by thedepositin of dust in the air currents which pass t rough the clay tileand not through the denser concrete. Also rust stains from the metallath are eliminated.

surface eliminates Clay tile contains oXids, salts, etc., which work outto the surface of the plaster causing efilorescence and stains.

It is obvious that various changes may be made in the form, constructionand arrange ment of the parts without departing from, the spirit andscope of the invention or sacrificing any of its material advantages,the form hereinbefore described being merely preferred embodimentsthereof.

I claim:

1. A method of making cores for concrete floor construction, whichcomprises disposing a layer of plaster in a plastic condition betweensheets of a permanent reinforcing material, subjecting the mass topressure,

whereby the plaster is incorporated with the reinforcing material toform a sheet of plaster board, subsequently molding said sheet whilestill in a plastic condition, and allowing the plaster toset.

2. A method of making cores for concrete floor construction, whichcomprises disposing a layer of plaster in a plastic condition betweensheets of reinforcing material, subjecting the mass to pressure, wherebythe plaster is incorporated with the reinforcing material to form asheet of plaster board, molding said sheet while still in a plasticcondition, allowing the plaster to set, and impregnating the surface ofthe molded member with water-proofing material.

3. A method of making cores for concrete floor construction, whichcomprises disposing a layer of plaster in a plastic condition, andcontaining accelerating material, between sheets of a permanentreinforcing material, subjecting the mass to pressure, whereby theplaster is incorporated with the reinforcing material to form a sheet ofplaster board, subsequently molding said sheet while still in a plasticcondition, and allowing the plaster to set.

4. A method for making cores for concrete floor construction whichcomprises disposing a layer of plaster in a plastic condition, andcontaining accelerating material, between sheets of reinforcingmaterial, subjecting the mass to pressure, whereby the plaster isincorporated with the reinforcing material to form a sheet of plasterboard, molding said sheet while still in a plastic condition, andallowing the plaster to set, and impregnating the surface of the moldedmember with water-proofing material.

A method of making cores for concrete floor construction, whichcomprises disposing layers of plaster in a plastic condition betweenalternate layers of a permanent reinforcing material, subjecting themass to pressure, whereby the plaster is incorporated with thereinforcing material to form a sheet of plaster board, subsequentlymolding said sheet while still in a plastic condition, and allowing theplaster to set.

6. A continuous method of making cores for concrete floor construction,which comprises disposing a layer of plaster in a plastic conditionbetween opposite sheets of reinforcing material, subjecting the mass torolling pressure, whereby the plaster is incorporated with thereinforcing material to form a continuous sheet of plaster board,molding said sheet while still in a plastic condition, allowing theplaster to set, and separating the molded sheet into members of desiredlength.

7. A continuous method of making cores for concrete floor construction,which comprises disposing a layer of plaster in a plastic conditionbetween opposite sheets of reinforcing material, subjecting the mass torolling pressure, whereby the plaster is incorporated with thereinforcin material to form a continuous sheet of p aster board;

molding said sheet while still in a plastic condition, allowing theplaster to set, separating the molded sheet into members of desiredlength, and impregnating the surface of the members with water-proofingmaterial.

8. A continuous method of making cores for concrete floor construction,which comprises disposing layers of plaster in a plastic conditionbetween alternate layers of a fibrous reinforcing material, subjectingthe mass to rolling pressure, whereby the plaster is incorporated withthe reinforcing material to form a continuous sheet of plaster board,molding said sheet while still in a plastic condition, allowing saidplaster to set, and separating the molded sheet into members of thedesired length.

9. A continuous method of making cores for concrete floor construction,which comprises disposing layers of plaster in a plastic conditionbetween alternate layers of a fibrous reinforcing material, subjectingthe mass to rolling pressure, whereby ,the plaster is incorporated withthe reinforcin material to form a continuous sheet 0 plaster board,molding said sheet while still in a plastic condition, allowing saidplaster to set, separating the molded sheet into members of the desiredlength, and impregnating the surface of the members with water-proofingmaterial.

CHARLES F. HENNING.

Witnesses:

WM. 0. BELT, M. A. KIDDIE.

cm" of this patent may be obtained for five cents each, by addressingthe "Commissioner 01' intents. Wuhlngton, D. 0."

